We are quite a ways into the design of a small project and had a really awful problem with piping systems.

Our sprinkler designer uses several piping system types - in this case its called "Fire Protection Branch (classification: Fire Protection Wet)" & "Fire Protection Main (classification: Fire Protection Wet)".

For the project thus far (and several other Revit projects our office works in), the branch piping connects into the main sprinkler loop. When this happens, both pipes keep their system. Nothing is overridden, and the different pipe systems retain their normal lineweights, colors, properties, etc.

Somewhere along the line, our designer connected these pipes and the piping systems merged and ended up changing the pipe system of the entire sprinkler system to "Fire Protection Main". The project was sync'ed and we ended up having to revert to a backup (and lost about 5 man-hours of work) because I could not find a way to solve the problem. If I changed a pipe system from main to branch, it would (predictably) change every single pipe connected to it. I had the same problem trying to change the systems through the system browser menu.

Does anyone know how this could have happened, what to do to prevent this from happening again? If I have forgotten any details, please let me know and I'll do my best to describe. Hopefully it is an avoidable problem.

Thanks